Double Oven - 3kw limit?

mrsnow101

We have just had our kitchen refurbished. This involved switching from a gas to an electric hob.

Now unfortunately due to a number of !!!! ups from different people, without some significant electrical works - we cant use the double oven we have bought. Apparently the max load that the current spur can handle is 3kw. Our new oven is approx. 5.5kw.

I'm keen to avoid the electrical work as it will involve pulling up lots of floorboards through the house - an expensive and time consuming job.

Is it possible to buy a double oven that draws < 3kw? I have gone through virtually every listing on appliance direct, and the lowest I can find is approx. 4.5kw.

Any thoughts appreciated.

phill99

I fit kitchens for a living and have never come scriposs a doible oven at under 3kw.

Double ovens require a dedicated circuit with a 40amp breaker.

mrsnow101

I thought that would be the case, so thanks for confirming.

Looks like this c0ck up is going to cost me a packet!!

DevCoder

phill99 wrote: »

I fit kitchens for a living and have never come scriposs a doible oven at under 3kw.

Double ovens require a dedicated circuit with a 40amp breaker.

Although I agree in practice, the breaker should be rated for the cable, its not there to protect the device at the end.

5500/230 = ~ 24A

So with diversity
10A + 30% of 14A + 5A = 22A

So potentially you *could* run 4mm2 t&E in a dedicated radial.

Not that you would want to.

Open for debate on whether the diversity 30% is 30% of full load (i.e. 24A) or 30% of remainder (i.e. 14A)

DevCoder

Hmm, just re-read the OSG.

First 10A
Then 30% of remainder = (30 * (24 -10)) /100 = (30*14) /100 = 4.2
Plus 5A for socket allowance
= 10A + 4.2A + 5A = 19.2A

So still a dedicated circuit

phill99

krisdorey wrote: »

Although I agree in practice, the breaker should be rated for the cable, its not there to protect the device at the end.

5500/230 = ~ 24A

So with diversity
10A + 30% of 14A + 5A = 22A

So potentially you *could* run 4mm2 t&E in a dedicated radial.

Not that you would want to.

Open for debate on whether the diversity 30% is 30% of full load (i.e. 24A) or 30% of remainder (i.e. 14A)

I've no doubt that to those in the know, your calculations are fascinating. I'm sure generations of electricians have discussed diversity while drinking real ale.

To the OP it is completely irrelevant as the question posed still hasn't been answered.

DevCoder

Well the simple answer is.

1. the 5.5kw oven is a no go other than on the cable/breaker according to my calcs (although they would want to get their own electrician to check it)
2. that any substitute would have to draw under 3kw to be even in consideration and as you and I know there are next to none that do that.

So with your and my posts the question has been answered, I was just disputing the need for a 40amp breaker as your post read that all double ovens need a 40amp breaker, when the breaker is not there for the ovens sake but rather the cable supplying it.

Avoriaz

mrsnow101 wrote: »

...Now unfortunately due to a number of !!!! ups from different people, without some significant electrical works - we cant use the double oven we have bought. Apparently the max load that the current spur can handle is 3kw. Our new oven is approx. 5.5kw.

I'm keen to avoid the electrical work as it will involve pulling up lots of floorboards through the house - an expensive and time consuming job......

Who was responsible for the !!!!ups and can you get them to pay to rectify the situation?

Surely an adequate power supply is a very basic consideration when planning a kitchen refurbishment.

Avoriaz

krisdorey wrote: »

Well the simple answer is.

1. the 5.5kw oven is a no go other than on the cable/breaker according to my calcs (although they would want to get their own electrician to check it)
2. that any substitute would have to draw under 3kw to be even in consideration and as you and I know there are next to none that do that.

So with your and my posts the question has been answered, I was just disputing the need for a 40amp breaker as your post read that all double ovens need a 40amp breaker, when the breaker is not there for the ovens sake but rather the cable supplying it.

Does this help?

mrsnow101

Avoriaz wrote: »

Who was responsible for the !!!!ups and can you get them to pay to rectify the situation?

Surely an adequate power supply is a very basic consideration when planning a kitchen refurbishment.

Confusion, crossed wires, no one in B&Q able to help, me not sending sufficient info the the guys doing the fitting. A combination of factors. Its happened, we've just got to deal with it.

We're going to avoid the re-wiring and will look to exchange the double oven for a single. Possibly get an integrated microwave as well - we'll see.

Appreciate the replies.

Avoriaz

Can you run a cable around the house or via some route that would avoid lifting floorboards?